/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.table.runtime.arrow;

import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.testutils.CustomEqualityMatcher;
import org.apache.flink.testutils.DeeplyEqualsChecker;
import org.apache.flink.util.Preconditions;

import org.apache.arrow.vector.ipc.ArrowStreamWriter;
import org.junit.Test;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import static org.junit.Assert.assertThat;
import static org.junit.Assert.fail;

/**
 * Abstract test base for {@link ArrowReader} and {@link ArrowWriter}.
 *
 * @param <T> the elment type.
 */
public abstract class ArrowReaderWriterTestBase<T> {

	private final DeeplyEqualsChecker checker;

	ArrowReaderWriterTestBase() {
		this.checker = new DeeplyEqualsChecker();
	}

	ArrowReaderWriterTestBase(DeeplyEqualsChecker checker) {
		this.checker = Preconditions.checkNotNull(checker);
	}

	@Test
	public void testBasicFunctionality() {
		try {
			ByteArrayOutputStream baos = new ByteArrayOutputStream();
			Tuple2<ArrowWriter<T>, ArrowStreamWriter> tuple2 = createArrowWriter(baos);
			ArrowWriter<T> arrowWriter = tuple2.f0;
			ArrowStreamWriter arrowStreamWriter = tuple2.f1;

			T[] testData = getTestData();
			for (T value : testData) {
				arrowWriter.write(value);
			}
			arrowWriter.finish();
			arrowStreamWriter.writeBatch();

			ArrowReader<T> arrowReader = createArrowReader(new ByteArrayInputStream(baos.toByteArray()));
			for (int i = 0; i < testData.length; i++) {
				T deserialized = arrowReader.read(i);
				assertThat("Deserialized value is wrong.",
					deserialized, CustomEqualityMatcher.deeplyEquals(testData[i]).withChecker(checker));
			}
		}
		catch (Exception e) {
			System.err.println(e.getMessage());
			e.printStackTrace();
			fail("Exception in test: " + e.getMessage());
		}
	}

	public abstract ArrowReader<T> createArrowReader(InputStream inputStream) throws IOException;

	public abstract Tuple2<ArrowWriter<T>, ArrowStreamWriter> createArrowWriter(OutputStream outputStream) throws IOException;

	public abstract T[] getTestData();
}
